This demo illustrates in a non-quantitative manner the forces experienced by a current carrying conductor in a magnetic field. A low-voltage/high-current power supply is used to supply the current to the conductor, which swings out from the gap of the horse-shoe magnet. The apparatus should not be operated for more than 5 seconds at a time as excessive heating of the flexible wire will occur.
The experiment can also be turned around: instead of current leads, a projection galvanometer can be attached to the rod, and the induced EMF measured as the rod moves through the magnetic field.